Originally Posted by
andrewclaus
In my limited experience, mainly working with donated bikes at non-profits, an incorrect spindle length is often manifested by the front derailleur not being able to reach the needed limits, up or down. On closer inspection, there's often chain rub against a larger chainring, or autoshifting off a larger chainring when cross-chained.
That's what happens with too long a spindle. If the spindle is too short, the chainring will scrape on the chainstay, and/or the crank arm will drag on the bottom bracket cup.